U.S. patent application number 17/023518 was filed with the patent office on 2021-01-07 for medical device.
This patent application is currently assigned to TERUMO KABUSHIKI KAISHA. The applicant listed for this patent is TERUMO KABUSHIKI KAISHA. Invention is credited to Takashi KITAOKA, Mizuho SHIRAISHI.
Application Number | 20210000494 17/023518 |
Document ID | / |
Family ID | |
Filed Date | 2021-01-07 |
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United States Patent
Application |
20210000494 |
Kind Code |
A1 |
KITAOKA; Takashi ; et
al. |
January 7, 2021 |
MEDICAL DEVICE
Abstract
A medical device capable of adjusting, while a rotating
expandable portion breaks an object, a breaking force of the
expandable portion. The medical device for breaking a thrombus in a
blood vessel includes a shaft portion, an expandable portion that
is provided to the shaft portion, a fixing portion that fixes the
expandable portion and the shaft portion, a slide portion that is
fixed to the expandable portion and is slidable with the shaft
portion, and an outer tube that houses therein the shaft portion,
in which the slide portion is movable by being indirectly pressed
by the outer tube, and the slide portion is relatively rotatable
relative to the outer tube.
Inventors: |
KITAOKA; Takashi;
(Hadano-city, JP) ; SHIRAISHI; Mizuho;
(Sagamihara-city, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TERUMO KABUSHIKI KAISHA |
Tokyo |
|
JP |
|
|
Assignee: |
TERUMO KABUSHIKI KAISHA
Tokyo
JP
|
Appl. No.: |
17/023518 |
Filed: |
September 17, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2019/011688 |
Mar 20, 2019 |
|
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17023518 |
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Current U.S.
Class: |
1/1 |
International
Class: |
A61B 17/221 20060101
A61B017/221 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2018 |
JP |
2018-064010 |
Claims
1. A medical device for destroying an object in a body lumen, the
medical device comprising: an axially movable outer tube possessing
an interior; an elongated shaft that is configured to be
rotationally driven, at least a part of the elongated shaft being
positioned in the interior of the outer tube, the outer tube and
the elongated shaft being relatively axially movable, the elongated
shaft possessing a distal end; an expandable portion positioned at
a distal portion of the elongated shaft, the expandable portion
being outwardly expandable from a contracted state to an expanded
state, the expandable portion possessing a distal end and a
proximal end; a fixing portion that fixes the distal end of the
expandable portion to the distal end of the shaft portion so that
axial movement of the elongated shaft in the axial direction
results in axial movement of the expandable portion in the axial
direction and so that rotation of the elongated shaft results in
rotation of the expandable portion; a slide portion that is
slidably mounted on the elongated shaft to slide in the axial
direction along the elongated shaft, the slide portion being fixed
to the proximal end of the expandable portion so that sliding
movement of the slide portion along the elongated shaft results in
sliding movement of the proximal end of each of the plurality of
wires along the elongated shaft; the slide portion is movable by
being directly or indirectly pressed by the outer tube; and the
slide portion and the outer tube being relatively rotatable with
respect to one another.
2. The medical device according to claim 1, further comprising an
interlock portion that is fixed to the slide portion so that axial
movement of the interlock portion results in axial movement of the
slide portion, the interlock portion being movable in the axial
direction relative to and along the shaft portion; the outer tube
including a press-side engagement portion that protrudes in a
radial direction and moves together with the outer tube; the
interlock portion including a movement-side engagement portion that
protrudes in the radial direction on a distal side or a proximal
side of the press-side engagement portion, the movement-side
engagement portion and the press-side engagement portion being
movable into a contacting engagement with one another and out of
contacting engagement with one another when the interlock portion
is moved in the axial direction relative to the shaft portion; and
axial movement of the outer tube in the axial direction causing the
press-side engagement portion to axially move in the axial
direction and move into contacting engagement with the
movement-side engagement portion, the contacting engagement between
the press-side engagement portion and the movement-side engagement
portion during the axial movement of the outer tube in the axial
direction causing the interlock portion and the slide portion to
axially move in the axial direction relative to the elongated
shaft.
3. The medical device according to claim 2, wherein the
movement-side engagement portion includes a first movement-side
engagement portion that protrudes in the radial direction on the
distal side of the press-side engagement portion, and the axial
movement of the outer tube toward the distal side relative to the
shaft portion causes the press-side engagement portion to move into
contacting engagement with the first movement-side engagement
portion.
4. The medical device according to claim 2, wherein the
movement-side engagement portion includes a second movement-side
engagement portion that protrudes in the radial direction on the
proximal side of the press-side engagement portion, and the axial
movement of the outer tube toward the proximal side relative to the
shaft portion causes the press-side engagement portion to move into
contacting engagement with the second movement-side engagement
portion.
5. The medical device according to claim 2, wherein the expanded
state is a first expanded state of the expandable portion, the
first expanded state being a natural state of the expandable
portion in which no force is applied to the expandable portion, and
the expandable portion expanding outwardly in the radial direction
more than in the first expanded state by the movement-side
engagement portion moving to the distal side relative to the shaft
portion.
6. The medical device according to claim 2, wherein the press-side
engagement portion is separable from the movement-side engagement
portion so that the press-side engagement portion moves out of
contacting engagement with the movement-side engagement
portion.
7. The medical device according to claim 2, wherein the elongated
shaft includes a center axis, the press-side engagement portion and
the movement-side engagement portion each including axially
opposite end surfaces that are perpendicular to the center axis of
the shaft portion.
8. The medical device according to claim 2, wherein the interlock
portion includes a first receiving portion possessing an inner
peripheral surface that slides along an outer peripheral surface of
the elongated shaft, and a second receiving portion spaced
proximally from the first receiving portion and possessing an inner
peripheral surface that slides along an outer peripheral surface of
the outer tube.
9. The medical device according to claim 1, wherein the slide
portion is in contact with a guide portion that is fixed to the
elongated shaft, the guide portion preventing rotation of the slide
portion relative to the elongated shaft and transmitting a rotation
force applied by rotation of the elongated shaft to the slide
portion.
10. A medical device for destroying an object in a body lumen, the
medical device comprising: an axially movable outer tube possessing
an interior; an elongated shaft that is configured to be
rotationally driven, at least a part of the elongated shaft being
positioned in the interior of the outer tube, the outer tube and
the elongated shaft being relatively axially movable in an axial
direction, the elongated shaft possessing a distal end; an
expandable portion comprised of a plurality of wires each having
shape memory characteristics, each of the wires possessing a distal
end and a proximal end, the expandable portion possessing an
intermediate portion, the plurality of wires at least in the
intermediate part of the expandable portion being spaced apart from
one another, the expandable portion being outwardly expandable from
a contracted state to an expanded state by virtue of a self-elastic
force of each of the plurality of wires, the expandable portion
moving a first distance in the axial direction as the expandable
portion moves from the contracted state to the expanded state, the
expandable portion in the expanded state possessing a first outer
diameter; a fixing portion that fixes the distal end of each of the
plurality of wires to the distal end of the elongated shaft; a
slide portion that is slidably mounted on the elongated shaft to
slide in the axial direction along the elongated shaft, the slide
portion being axially slidable in the axial direction relative to
the elongated shaft, the slide portion being fixed to the proximal
end of each of the plurality of wires so that sliding movement of
the slide portion along the elongated shaft results in sliding
movement of the proximal end of each of the plurality of wires
along the elongated shaft; a distal side stopper and a proximal
side stopper fixed to the elongated shaft to restrict movement of
the slide portion; an axial distance between the distal side
stopper and the proximal side stopper is greater than the first
distance; and the expandable portion expanding outwardly from the
first outer diameter to a second outer diameter that is larger than
the first outer diameter when the outer tube is moved in the axial
direction by a second distance so that the slide portion moves
toward the distal side stopper.
11. The medical device according to claim 10, wherein the first
distance is greater than the second distance.
12. The medical device according to claim 10, further comprising an
interlock portion through which passes the elongated shaft, and the
interlock portion being movable in the axial direction along the
shaft portion; the outer tube including a press-side engagement
portion that protrudes in a radial direction; the interlock portion
including a movement-side engagement portion that protrudes in the
radial direction on a distal side or a proximal side of the
press-side engagement portion, the movement-side engagement portion
and the press-side engagement portion being movable into a
contacting engagement with one another and out of contacting
engagement with one another when the interlock portion is moved in
the axial direction relative to the shaft portion; and axial
movement of the outer tube in the axial direction causing the
press-side engagement portion to axially move in the axial
direction and move into contacting engagement with the
movement-side engagement portion, the contacting engagement between
the press-side engagement portion and the movement-side engagement
portion during the axial movement of the outer tube in the axial
direction causing the interlock portion and the slide portion to
axially move in the axial direction relative to the elongated
shaft.
13. The medical device according to claim 10, wherein the interlock
portion is connected to the slide portion so that the interlock
portion and the slide portion move together, the interlock portion
being independent of the outer tube and relatively rotatable
relative to the outer tube.
14. The medical device according to claim 10, wherein the axial
distance between the proximal side stopper and the slide portion
increases as the expandable portion moves from the contracted state
to the expanded state, and the axial distance between the distal
side stopper and the slide portion decreases as the expandable
portion moves from the contracted state to the expanded state.
15. The medical device according to claim 10, wherein the expanded
state of the expandable portion is a natural state of the
expandable portion in which no force is applied to the expandable
portion, the axial distance between the distal side stopper and the
slide portion when the expandable portion is in the expanded state
being greater than the first distance.
16. A method comprising: positioning an expandable portion in a
living body lumen in a living body while the expandable portion is
in a contracted state, the expandable portion being positioned at a
distal portion of an elongated shaft; moving the expandable portion
in the living body lumen to position the expandable portion
adjacent an object in the living body lumen that is to be cut;
expanding the expandable portion from the contracted state to a
first expanded state to increase an outer size of the expandable
portion; rotating the expandable portion while the expandable
portion is in the first expanded state to cause the rotating
expandable portion in the first expanded state to cut the object;
further expanding the expandable portion from the first expanded
state to a second expanded state in which the outer size of the
expandable portion in the second expanded state is greater than the
outer size of the expandable portion in the first expanded state,
the further expanding of the expandable portion from the first
expanded state to the second expanded state occurring while the
expandable portion is rotating; and rotating the expandable portion
while the expandable portion is in the second expanded state to
cause the rotating expandable portion in the second expanded state
to further cut the object.
17. The method according to claim 16, wherein the positioning of
the expandable portion in the living body lumen includes
positioning the expandable portion in the living body lumen while
the expandable portion is in the contracted state inside a sheath
having an open distal end so that a distal end of the expandable
portion is proximal of the open distal end of the sheath.
18. The method according to claim 17, wherein the expanding of the
expandable portion from the contracted state to the first expanded
state comprises relatively moving the expandable portion and the
sheath so that the expandable portion passes through the open
distal end of the sheath and is positioned completely outside the
sheath, the expandable portion expanding to the first expanded
state by virtue of a self-expanding force of the expandable
portion, the first expanded state of the expandable portion being a
natural state of the expandable portion in which no force is
applied to the expandable portion.
19. The method according to claim 16, wherein the expandable
portion includes a proximal portion connected to a slide piece that
is slidably mounted on the elongated shaft, the slide piece being
connected to an outer tube by way of a linking portion so that
axial movement of the outer tube results in sliding movement of the
slide piece on the elongated shaft, the further expanding of the
expandable portion from the first expanded state to the second
expanded state comprising axially moving the outer tube in a distal
direction to cause the slide piece to axially move in the distal
direction by way of the linking portion.
20. The method according to claim 19, further comprising causing
the elongated shaft to bend to produce a bent elongated shaft by
axially moving the outer tube in a proximal direction to cause the
slide piece to axially move in the proximal direction by way of the
linking portion, the method further comprising rotating the
expandable portion while the shaft is bent and cutting the object
during the rotating of the expandable portion while the shaft is
bent.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of International
Application No. PCT/JP2019/011688 filed on Mar. 20, 2019, which
claims priority to Japanese Patent Application No. 2018-064010
filed on Mar. 29, 2018, the entire content of both of which is
incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This disclosure generally relates to a medical device for
removing an object in a body lumen.
BACKGROUND DISCUSSION
[0003] A thrombus generated in a body lumen needs to be promptly
removed. A known method for treating a thrombus involves breaking
and removing the thrombus by an inflation portion provided at a
distal side of an elongated shaft portion. The inflation portion
changes an inflated diameter thereof depending on a change in
length in an axial direction.
[0004] For example, JP-T 2003-504090 describes a device that cuts a
thrombus in a coronary artery. This device is provided with a
rotating body at a distal portion of a catheter, wherein an
abradant is adhered to the outer surface of the rotating body. This
device rotates the rotating body in the coronary artery, thereby
cutting a stenosis substance by the abradant. The rotating body of
this device is provided with four bars that are arranged in a
circumferential direction. The rotating body is capable of
inflating in accordance with a diameter of a blood vessel by
bending and protruding the bars radially outward.
SUMMARY
[0005] When an object to be broken is difficult to break, there may
be a desire to increase the breaking force. However, the
abovementioned device described in JP-T 2003-504090 cannot change
the inflated diameter of the bar when the rotating body is
rotating.
[0006] The medical device disclosed here allows adjustment of a
breaking force of an expandable portion when the rotating
expandable portion breaks an object.
[0007] A medical device disclosed here is able to destroy (e.g.,
crush or cut) an object in a body lumen. The medical device
includes an axially movable outer tube possessing an interior, an
elongated shaft that is configured to be rotationally driven, and
an expandable portion positioned at a distal portion of the
elongated shaft. At least a part of the elongated shaft is
positioned in the interior of the outer tube, and the outer tube
and the elongated shaft are relatively axially movable. The
expandable portion is outwardly expandable from a contracted state
to an expanded state. A fixing portion fixes the distal end of the
expandable portion to the distal end of the shaft portion so that
axial movement of the elongated shaft in the axial direction
results in axial movement of the expandable portion in the axial
direction and so that rotation of the elongated shaft results in
rotation of the expandable portion. A slide portion is slidably
mounted on the elongated shaft to slide in the axial direction
along the elongated shaft, wherein the slide portion is fixed to
the proximal end of the expandable portion so that sliding movement
of the slide portion along the elongated shaft results in sliding
movement of the proximal end of the expandable portion along the
elongated shaft. The slide portion is movable by being directly or
indirectly pressed by the outer tube, and the slide portion and the
outer tube are relatively rotatable with respect to one
another.
[0008] In the medical device configured as the above, the slide
portion can be caused to move to the distal side or the proximal
side by causing the outer tube to move in the axial direction. The
slide portion moves to the distal side or the proximal side to
deform the inflation portion that is positioned between the fixing
portion and the slide portion. In addition, the interlock portion
relatively rotates relative to the outer tube. Therefore, in the
medical device, during when the rotating inflation portion is
breaking the object, it is possible to adjust the breaking force of
the inflation portion and to prevent the rotation force from the
rotating slide portion from being transmitted to the outer tube,
which results in an easy operation by an operator.
[0009] According to another aspect, a medical device for destroying
an object in a body lumen comprises: an axially movable outer tube
possessing an interior; an elongated shaft that is configured to be
rotationally driven; and an expandable portion. At least a part of
the elongated shaft is positioned in the interior of the outer
tube, and the outer tube and the elongated shaft are relatively
axially movable in an axial direction. The expandable portion is
comprised of a plurality of wires each having shape memory
characteristics. The plurality of wires at least in the
intermediate part of the expandable portion being spaced apart from
one another, and the expandable portion being outwardly expandable
from a contracted state to an expanded state by virtue of a
self-elastic force of each of the plurality of wires, with the
expandable portion moving a first distance in the axial direction
as the expandable portion moves from the contracted state to the
expanded state, and the expandable portion in the expanded state
possessing a first outer diameter. A fixing portion fixes the
distal end of each of the plurality of wires to the distal end of
the elongated shaft, and a slide portion is slidably mounted on the
elongated shaft to slide in the axial direction along the elongated
shaft. The slide portion is axially slidable in the axial direction
relative to the elongated shaft, and is fixed to the proximal end
of each of the plurality of wires so that sliding movement of the
slide portion along the elongated shaft results in sliding movement
of the proximal end of each of the plurality of wires along the
elongated shaft. A distal side stopper and a proximal side stopper
are fixed to the elongated shaft to restrict movement of the slide
portion, and the axial distance between the distal side stopper and
the proximal side stopper is greater than the first distance. The
expandable portion expands outwardly from the first outer diameter
to a second outer diameter that is larger than the first outer
diameter when the outer tube is moved in the axial direction by a
second distance so that the slide portion moves toward the distal
side stopper.
[0010] In accordance with another aspect, a method comprises
positioning an expandable portion in a living body lumen in a
living body while the expandable portion is in a contracted state,
wherein the expandable portion is positioned at a distal portion of
an elongated shaft; moving the expandable portion in the living
body lumen to position the expandable portion adjacent an object in
the living body lumen that is to be cut; expanding the expandable
portion from the contracted state to a first expanded state to
increase an outer size of the expandable portion; rotating the
expandable portion while the expandable portion is in the first
expanded state to cause the rotating expandable portion in the
first expanded state to cut the object; and further expanding the
expandable portion from the first expanded state to a second
expanded state in which the outer size of the expandable portion in
the second expanded state is greater than the outer size of the
expandable portion in the first expanded state. The further
expanding of the expandable portion from the first expanded state
to the second expanded state occurs while the expandable portion is
rotating. The method additionally involves rotating the expandable
portion while the expandable portion is in the second expanded
state to cause the rotating expandable portion in the second
expanded state to further cut the object.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a plan view illustrating a medical device
according to an embodiment.
[0012] FIG. 2 is an enlarged plan view illustrating a distal
portion of the medical device.
[0013] FIGS. 3(A) and 3(B) depict cross-sectional views
illustrating the distal portion of the medical device: FIG. 3(A)
illustrates a state where an expandable portion has expanded; and
FIG. 3(B) illustrates a state where the expandable portion has
contracted.
[0014] FIG. 4 is a cross-sectional view illustrating a state where
the expandable portion is caused to further outwardly expand in a
blood vessel.
[0015] FIG. 5 is a cross-sectional view illustrating a state where
a shaft portion is curved in the blood vessel.
[0016] FIG. 6 is a cross-sectional view illustrating a modification
example of the medical device.
DETAILED DESCRIPTION
[0017] Set forth below with reference to the accompanying drawings
is a detailed description of embodiments of a medical device and
method of use representing examples of the inventive medical device
and method disclosed here. The dimensions or scales on the drawings
may be exaggerated or different from actuality/reality for
convenience of description and illustration.
[0018] A medical device 10 according to one embodiment disclosed by
way of example is inserted into a blood vessel in a deep venous
thrombosis, and is used for a procedure to break the thrombus. In
the present description, a side of a device to be inserted into the
blood vessel is referred to a "distal side" or "distal end", and a
hand-side where the device is operated is referred to as a
"proximal side" or "proximal end". An object to be broken through
use of the medical device and method disclosed here is not
necessarily limited to a thrombus, and all objects that can exist
in a body lumen can be corresponded.
[0019] The medical device 10 includes, as illustrated in FIGS. 1,
2, and 3(A), a shaft portion 20, an outer tube 30, an expandable
portion 60, a fixing portion 40, a slide portion 50, an interlock
portion 70, an operation unit 80, and a driving unit 90.
[0020] The shaft portion (shaft) 20 is a portion that transmits a
rotation force to the expandable portion 60. The shaft portion 20
is provided with a shaft body (shaft) 21, a guide convex portion
22, a distal side stopper 23, a proximal side stopper 24, and a hub
25. The shaft body 21 is an elongated tubular body that transmits
the rotation force from a proximal portion of the shaft body 21 to
a distal portion of the shaft body 21. The proximal portion of the
shaft body 21 penetrates through the operation unit 80. The
proximal portion of the shaft body 21 is rotatably connected to the
operation unit 80. The shaft body 21 has flexibility so as to be
able to move in the blood vessel. In addition, the shaft body 21
has preferably high torsional rigidity so as to be able to transmit
the rotation force from the proximal portion of the shaft body 21
to the distal portion of the shaft body 26. The shaft portion 20
is, for example, a tubular body made of metal in which a
spiral-shaped slit is formed. Examples of a material from which the
shaft portion 20 may be made include stainless steel.
[0021] The hub 25 is fixed to a proximal end of the shaft body 21.
The hub 25 allows a guide wire to be inserted therethrough.
[0022] The guide convex portion 22 is fixed to an outer peripheral
surface of the shaft body 21 at a distal portion of the shaft body
21 so that the guide convex portion 22 moves together with the
shaft body 21. The guide convex portion 22 is elongated, and is
disposed parallel to an axial center or center axis of the shaft
body 21. The guide convex portion 22 restricts or prevents the
rotation of the slide portion 50, and transmits the rotation force
to the slide portion 50. Moreover, the guide convex portion 22
causes the slide portion 50 to move along the central axis of the
shaft body 21.
[0023] The distal side stopper 23 is a ring-shaped member that is
fixed to the outer peripheral surface of the shaft body 21 on the
distal side of the guide convex portion 22. The distal side stopper
23 restricts movement of the slide portion 50 to the distal side or
in the distal direction. The proximal side stopper 24 is a
ring-shaped member that is fixed to the outer peripheral surface of
the shaft body 21 on the proximal side of the guide convex portion
22. The proximal side stopper 24 restricts the movement of the
slide portion 50 to the proximal side or in the proximal
direction.
[0024] The fixing portion 40 is a tubular member that fixes the
expandable portion 60 to the shaft portion 20. The fixing portion
40 is fixed to the outer peripheral surface of the shaft body 21 at
a distal end of the shaft body 21. In addition, the fixing portion
40 is fixed to a distal end of the expandable portion 60.
[0025] The slide portion or slide piece 50 is a member that is
slidably positioned on the outer peripheral surface of the shaft
body 21 on the proximal side from the fixing portion 40. A proximal
end of the expandable portion 60 is fixed to the slide portion 50.
The slide portion 50 has an approximately C-character shape in a
cross-section orthogonal to the central axis of the shaft body 21.
In other words, an axially extending slit-shaped guide groove 51 is
formed in the slide portion 50 from a distal end of the slide
portion 50 to a proximal end of the slide portion 50. The guide
convex portion 22 is disposed in the guide groove 51. Accordingly,
the slide portion 50 is capable of sliding on and relative to the
outer peripheral surface of the shaft body 21 in the axial
direction along the guide convex portion 22. Moreover, the rotation
of the slide portion 50 is restricted or prevented by the guide
convex portion 22. Accordingly, when the shaft portion 20 rotates,
the slide portion 50 receives the rotation force from the guide
convex portion 22. Therefore, the slide portion 50 is movable in
the axial direction relative to and along the shaft portion 20, and
can rotate together with the shaft portion 20.
[0026] The expandable portion 60 is a portion that outwardly
expands in the body lumen, and rotates to break an object such as a
thrombus. The expandable portion 60 is provided at the distal
portion of the shaft portion 20. The expandable portion 60 includes
a plurality of (six in the present embodiment) wire rods 61. Each
of the wire rods 61 is three-dimensionally curved. The number of
the wire rods 61 is not specially limited. Moreover, the
cross-sectional shape of wire rod 61 is not specially limited. A
twist toward the same circumferential direction is applied to each
of the wire rods 61 along the axial direction of the shaft portion
20, meaning each of the wire rods extends in a helical manner as
shown in FIG. 2. As illustrated, the wires or wire rods 61 are
separate from one another and spaced apart from one another at
least in the axially intermediate portion of the expandable portion
60. Distal ends of the respective wire rods 61 are fixed to the
fixing portion 40. Proximal ends of the respective wire rods 61 are
fixed to the slide portion 50. Fixed positions of the respective
wire rods 61 relative to the fixing portion 40 and the slide
portion 50 are aligned in the circumferential direction. Moreover,
curved approximately center parts of the respective wire rods 61
are aligned in the circumferential direction at positions distant
from the shaft portion 20 in the radial direction. Accordingly, the
expandable portion 60 has a uniform swelling in the circumferential
direction as a whole. The expandable portion 60 becomes a first
expanded state in a natural state where no external force acts.
When the shaft portion 20 rotates, the expandable portion 60 also
rotates with the rotation, and can break a thrombus in the blood
vessel and stir the broken thrombi.
[0027] The wire rods 61 included in the expandable portion 60 are
each a relatively thin member made of metal and having flexibility.
The expandable portion 60 is in a state of being housed in an
inside of a sheath 100 before reaching a target site in the blood
vessel, as illustrated in FIG. 3(B). The sheath 100 may be of a
known construction. When the expandable portion 60 is inserted into
or positioned in the sheath 100, the slide portion 50 moves along
the shaft portion 20 to the proximal side, and is separated from
the fixing portion 40. Accordingly, the wire rods 61 are reduced in
diameter and housed in an inside of the sheath 100. After the shaft
portion 20 is inserted to or positioned at the target site in the
blood vessel, the sheath 100 is caused to move to the proximal side
relative to the shaft portion 20. Accordingly, as illustrated in
FIGS. 2 and 3(A), the expandable portion 60 is exposed to an
outside of the sheath 100 at a position distal of the distal end of
the sheath 100, and automatically expands by a self-elastic or
self-expanding force of the expandable portion 60. At this time,
the slide portion 50 moves along the shaft portion 20 to the distal
side or in the distal direction.
[0028] The wire rods 61 desirably include a material having shape
memory characteristics so as to be highly elastically deformed.
Examples of a material from which the wire rods 61 may be made
include a shape memory alloy to which a shape memory effect and
super elasticity are applied by thermal processing, stainless
steel, and the like. As for a shape memory alloy, Ni--Ti-based,
Cu--Al--Ni-based, Cu--Zn--Al-based alloys, combinations thereof,
and the like are suitable.
[0029] The outer tube 30 is a member that transmits a movement
force toward the axial direction at a hand-side (proximal end) to
the distal side. The outer tube 30 includes an outer tube main body
31 and a press-side engagement portion 32. The outer tube main body
31 is a tubular body that rotatably houses therein the rotating
shaft body 21. The outer tube main body 31 has flexibility so as to
be able to move in the blood vessel. The outer tube main body 31 is
movable in the axial direction along the shaft body 21. A proximal
portion of the outer tube main body 31 is positioned in an inside
of the operation unit 80. The press-side engagement portion 32 is a
ring-shaped member that is fixed to an outer peripheral surface of
the outer tube main body 31 at a distal end of the outer tube main
body 31. The press-side engagement portion 32 protrudes from the
outer peripheral surface of the outer tube main body 31 outward in
the radial direction. A surface on the distal side of and a surface
on the proximal side of the press-side engagement portion 32 are
approximately perpendicular to the center axis of the shaft portion
20.
[0030] The interlock portion 70 is a tubular body that transmits
the movement force of the outer tube 30 toward the axial direction
to the slide portion 50. The interlock portion 70 includes a distal
side fixing portion 78, a movement-side engagement portion 71, a
first receiving portion 74, a second receiving portion 75, a first
tubular portion 76, and a second tubular portion 77. The
movement-side engagement portion 71 is provided with a first
movement-side engagement portion 72, and a second movement-side
engagement portion 73. The distal side fixing portion 78 covers the
slide portion 50, and is fixed to the slide portion 50.
[0031] The first movement-side engagement portion 72 is a portion
that is capable of attaching to or engaging with (directly
contacting) the press-side engagement portion 32. The first
movement-side engagement portion 72 is positioned on the proximal
side from the distal side fixing portion 78. The first
movement-side engagement portion 72 protrudes inward in the radial
direction. The first movement-side engagement portion 72 is
positioned on the distal side of the press-side engagement portion
32. A surface on the proximal side of the first movement-side
engagement portion 72 is approximately perpendicular to the axial
center of the shaft portion 20. An inner diameter of the first
movement-side engagement portion 72 is larger than an outer
diameter of the shaft body 21, and is smaller than an outer
diameter of the press-side engagement portion 32. Accordingly, a
surface on the proximal side of the first movement-side engagement
portion 72 is capable of attaching to or engaging with the
press-side engagement portion 32 that moves to the distal side.
[0032] The second movement-side engagement portion 73 is a portion
capable of attaching to or engaging with (directly contacting) the
press-side engagement portion 32. The second movement-side
engagement portion 73 is positioned on the proximal side from the
first movement-side engagement portion 72. The second movement-side
engagement portion 73 protrudes inward in the radial direction. The
second movement-side engagement portion 73 is positioned on the
proximal side of the press-side engagement portion 32. A surface on
the distal side of the second movement-side engagement portion 73
is approximately perpendicular to the axial center of the shaft
portion 20. An inner diameter of the second movement-side
engagement portion 73 is larger than the outer diameter of the
outer tube main body 31, and is smaller than the outer diameter of
the press-side engagement portion 32. Accordingly, the surface on
the distal side of the second movement-side engagement portion 73
is capable of attaching to or engaging with the press-side
engagement portion 32 that moves to the proximal side.
[0033] The first receiving portion 74 is formed continuously from
the first movement-side engagement portion 72 on the distal side of
the first movement-side engagement portion 72. An inner peripheral
surface of the first receiving portion 74 comes into close contact
with the outer peripheral surface of the shaft body 21 with a
prescribed clearance. The inner peripheral surface of the first
receiving portion 74 is capable of smoothly sliding with respect to
and along the outer peripheral surface of the shaft body 21.
[0034] The second receiving portion 75 is formed continuously from
the second movement-side engagement portion 73 on the proximal side
of the second movement-side engagement portion 73. An inner
peripheral surface of the second receiving portion 75 comes into
close contact with the outer peripheral surface of the outer tube
main body 31 with a prescribed clearance. The inner peripheral
surface of the second receiving portion 75 is capable of smoothly
sliding with respect to and along the outer peripheral surface of
the outer tube main body 31.
[0035] The first tubular portion 76 is a tubular portion that is
positioned between the distal side fixing portion 78 and the first
receiving portion 74. An inner diameter of the first tubular
portion 76 is larger than an outer diameter of the proximal side
stopper 24. Accordingly, the first tubular portion 76 provides an
internal space in which the proximal side stopper 24 is movable in
the axial direction.
[0036] The second tubular portion 77 is a tubular portion that is
positioned between the first movement-side engagement portion 72
and the second movement-side engagement portion 73. An inner
diameter of the second tubular portion 77 is larger than the outer
diameter of the press-side engagement portion 32. Accordingly, the
second tubular portion 77 provides an internal space in which the
press-side engagement portion 32 is movable in the axial direction.
A length of the second tubular portion 77 in the axial direction is
longer than a length of the press-side engagement portion 32 in the
axial direction. Therefore, the press-side engagement portion 32 is
movable in the axial direction in the inside of the second tubular
portion 77 that is positioned between the first movement-side
engagement portion 72 and the second movement-side engagement
portion 73.
[0037] The interlock portion 70 preferably has flexibility greater
than and has flexural rigidity less than the shaft portion 20 so as
not to hinder an operation of the shaft portion 20. A Examples of a
material from which the interlock portion 70 may be made is not
specially limited Examples of the material from which the interlock
portion 70 may be made include thermoplastic polyester elastomer,
polyolefin such as polyethylene or polypropylene, polyamide,
polyester such as polyethylene terephthalate, a fluorinated polymer
such as polytetrafluoroethylene (PTFE) or tetrafluoroethylene
ethylene copolymer (ETFE), polyether ether ketone (PEEK),
polyimide.
[0038] The operation unit 80 is a portion that is gripped and
operated by an operator. The operation unit 80 is provided with, as
illustrated in FIG. 1, a casing 81, a first gear 82 that is fixed
to the shaft body 21, and an operation handle 83 that is fixed to
the outer tube 30. The casing 81, through which the shaft portion
20 penetrates, houses therein a proximal end of the outer tube 30.
A part of the first gear 82 is disposed in the casing 81, and
another part of the first gear 82 is exposed outward from an
opening portion 84 of the casing 81. A part of the operation handle
83 is disposed in the casing 81, and another part of the operation
handle 83 is positioned outward of the casing 81. The operation
handle 83 is movable in the axial direction relative to the casing
81. The operation handle 83 is fixed to the outer tube 30 in an
inside of the casing 81. Accordingly, the operation handle 83 moves
in the axial direction, whereby the outer tube 30 moves in the
axial direction relative to the shaft portion 20.
[0039] The driving unit 90 is a portion that rotationally drives
the shaft portion 20. The driving unit 90 is provided with a drive
source 91 such as a motor, a second gear 92 that is rotated by the
drive source 91, and a connector 93 that is interlocked with the
operation unit 80. The connector 93 is interlocked with the
operation unit 80, whereby the second gear 92 and the first gear 82
mesh with each other. Accordingly, the drive source 91 is rotated
to rotate the shaft portion 20. The drive source 91 is configured
to rotate in opposite directions. The drive source 91 is not
limited to one that rotates in opposite directions, but may rotate
in one direction.
[0040] A method of operating/using the medical device 10 according
to the above-described embodiment will be explained using a case
where a thrombus B in the blood vessel is broken as an example.
[0041] First, as illustrated in FIG. 3(B), the medical device 10 in
a state where the distal portion of the shaft portion 20 including
the expandable portion 60 is housed in the sheath 100 is prepared.
Next, a guide wire 110 (see FIG. 4) is inserted into the shaft
portion 20. Subsequently, the sheath 100 and the expandable portion
60 housed in the sheath 100 are moved in the blood vessel while
being guided along the guide wire 110 to reach the vicinity of the
thrombus B. Thereafter, when the sheath 100 is moved to the
proximal side relative to the medical device 10 or is moved in the
proximal direction, as illustrated in FIGS. 2 and 3(A), the
expandable portion 60 is exposed outside the sheath 100. That is,
the expandable portion 60 is exposed distal of the distal end of
the sheath 100. Accordingly, the expandable portion 60 expands by
the self-elastic force or self-expanding force, and shifts to a
first expanded state. At this time, the slide portion 50 slides
along the guide convex portion 22 on the outer peripheral surface
of the shaft body 21 to the distal side or in the distal direction.
When the expandable portion 60 shifts from a contracted state while
housed in the sheath 100 to the first expanded state upon automatic
outward expansion by virtue of the self-expanding force, the
expandable portion 60 moves by a first distance L1 in the axial
direction, and outwardly expands. In the first expanded state, a
second distance L2 between the distal side stopper 23 and the slide
portion 50 is longer than the first distance L1. Next, as
illustrated in FIG. 1, the driving unit 90 is interlocked with the
operation unit 80. Next, when the drive source 91 is operated
(i.e., when the driving source 91 is turned on), the shaft portion
20 rotates, and the fixing portion 40 and the guide convex portion
22 fixed to the shaft portion 20 rotate. Accordingly, the
expandable portion 60 rotates by receiving the rotation force from
the fixing portion 40, and the slide portion 50 interlocked with
the guide convex portion 22. Subsequently, when the expandable
portion 60 is caused to reciprocate in the axial direction in the
blood vessel, the expandable portion 60 comes into contact with the
thrombus B, and breaks the thrombus B. The expandable portion 60
repeats the rotation and the stop of rotation. Accordingly, the
expandable portion 60 repeats the operation of cutting into the
thrombus B at the stop of rotation, and scraping the thrombus B off
(crushing or destroying the thrombus B) by the rotation.
[0042] When the breaking force is desired to be increased, the
operation handle 83 is moved to the distal side or in the distal
direction. Accordingly, the outer tube 30 interlocked with the
operation handle 83 moves to the distal side or in the distal
direction. Accordingly, as illustrated in FIG. 4, the press-side
engagement portion 32 contacts or engages the first movement-side
engagement portion 72, and causes the first movement-side
engagement portion 72 to move to the distal side or in the distal
direction. That is, the press-side engagement portion 32 is brought
into contacting engagement with the first movement-side engagement
portion 72, and the first movement-side engagement portion 72 moves
in the axial direction together with the outer tube 30 and the
press-side engagement portion 32. Accordingly, the interlock
portion 70 and the slide portion 50 move to the distal side or in
the distal direction relative to the shaft portion 20. When the
slide portion 50 moves to the distal side, the distance between the
fixing portion 40 and the slide portion 50 becomes shorter or is
reduced. Accordingly, the expandable portion 60 outwardly expands
in the radial direction, thereby expanding to an outer size larger
than the outer size of the expandable portion 60 in the first
expanded state. Accordingly, as indicated by the black arrows in
FIG. 4, a portion of the expandable portion 60 already in contact
with the thrombus B in the first expanded state comes into stronger
contact with the thrombus B. Moreover, as indicated by the white
arrows in FIG. 4, a part of the expandable portion 60 not in
contact with the thrombus B in the first expanded state outwardly
expands in the radial direction and comes into contact with the
thrombus B. Therefore, the breaking force of the expandable portion
60 is increased. The operator can change the breaking force of the
expandable portion 60 by adjusting the movement amount of the
operation handle 83. When the operation handle 83 is moved to the
distal side or in the distal direction, the slide portion 50 moves
closer to the distal side stopper 23. When the slide portion 50
comes into contact with the distal side stopper 23, further
movement of the slide portion 50 is restricted or prevented.
Accordingly, for safety, further expansion of the expandable
portion 60 is restricted. The slide portion 50 can move to the
distal side from the self-expanded first state, within a range of
the second distance L2.
[0043] Moreover, when the breaking force is desired to be
increased, the operation handle 83 may be caused to move to the
proximal side. Accordingly, the outer tube 30 interlocked with the
operation handle 83 moves to the proximal side or in the proximal
direction. Accordingly, as illustrated in FIG. 5, the press-side
engagement portion 32 contacts or is engaged with the second
movement-side engagement portion 73, and causes the second
movement-side engagement portion 73 to move to the proximal side or
in the proximal direction. Therefore, the interlock portion 70 and
the slide portion 50 move to the proximal side relative to the
shaft portion 20. When the slide portion 50 moves to the proximal
side or in the proximal direction, a force toward the proximal side
acts on the fixing portion 40. Accordingly, the shaft body 21
having flexibility is curved in an inner side of the expandable
portion 60. When the shaft body 21 rotates in this state, the
distal end of the curved shaft body 21 swings around, the
expandable portion 60 rotates about the swung-around shaft body 21.
Therefore, an influence range of the expandable portion 60
increases. Accordingly, the breaking force of the expandable
portion 60 increases. The operator can change the breaking force of
the expandable portion 60 by adjusting the movement amount of the
operation handle 83.
[0044] After the thrombus B has been broken by the expandable
portion 60, the drive source 91 is stopped to stop the rotation of
the shaft portion 20. Next, the expandable portion 60 and the
sheath are relatively axially moved so that the expandable portion
60 is housed in the sheath 100. Next, the medical device 10 is
extracted from the blood vessel, and the procedure using the
medical device 10 is completed. The broken thrombus B is sucked
(e.g., aspirated) and removed by, for example, the sheath 100 or
another device.
[0045] The medical device 10 according to the present embodiment is
a medical device 10 for destroying (e.g., crushing or cutting) the
thrombus B (object) in the blood vessel (body lumen in a living
body), and includes: the elongated shaft portion 20 that is
rotationally driven; the expandable portion 60 that is provided to
the distal portion of the shaft portion 20; the fixing portion 40
to which the distal end of the expandable portion 60 and the shaft
portion 20 are fixed; the slide portion 50 that is fixed to the
proximal end of the expandable portion 60, and is interlocked with
the shaft portion 20 slidably in the axial direction; and the outer
tube 30 that houses therein the shaft portion 20, and is movable in
the axial direction along the shaft portion 20, in which the slide
portion 50 is movable by being indirectly pressed by the outer tube
30, and the slide portion 50 is relatively rotatable relative to
the outer tube 30. The outer tube 30 may be movable in the axial
direction along the shaft portion 20, and also rotatable.
[0046] In the medical device 10 configured in the manner described
above, the slide portion 50 can move to the distal side or the
proximal side by moving the outer tube 30 in the axial direction.
The slide portion 50 moves to the distal side or the proximal side
to deform the expandable portion 60 that is positioned between the
fixing portion 40 and the slide portion 50. Therefore, in the
medical device 10, during when the rotating expandable portion 60
breaks the thrombus B (object), it is possible to adjust the
breaking force of the expandable portion 60. In addition, the slide
portion 50 relatively rotates with respect to the outer tube 30.
Therefore, the rotation force is not so likely to be transmitted
from the rotating slide portion 50 to the outer tube 30, which
results in an easy operation by the operator.
[0047] Moreover, the medical device 10 includes the interlock
portion 70 that is fixed to and movable with the slide portion 50
and is movable in the axial direction along the shaft portion 20,
the outer tube 30 includes the press-side engagement portion 32
that protrudes in the radial direction, the interlock portion 70
includes the movement-side engagement portion 71 that protrudes in
the radial direction on at least one of the distal side and
proximal side of the press-side engagement portion 32, and the
interlock portion 70 is moved because the press-side engagement
portion 32 is engaged or in contact with the movement-side
engagement portion 71 by the outer tube 30, and causes the slide
portion 50 to move. Accordingly, in the medical device 10, it is
possible to indirectly press the slide portion 50 via the interlock
portion 70 by the outer tube 30. Therefore, by disposing the
interlock portion 70 having a structure desired to cause the slide
portion 50 to move, it is possible to effectively cause the slide
portion 50 to move. The interlock portion 70 may be movable in the
axial direction along the shaft portion 20, and also rotatable.
Moreover, the interlock portion 70 is fixed to the slide portion
50, but does not need to be completely fixed to the slide portion.
For example, the interlock portion 70 and the slide portion 50 may
be fixed to each other to the extent that the interlock portion 70
and the slide portion 50 mutually constrain the movement and can
integrally move together as a unit.
[0048] Also, the interlock portion 70 is connected to the slide
portion 50 and is independent of the outer tube 30, and thus is
relatively rotatable relative to the outer tube 30. Accordingly,
the outer tube 30 is not connected to but is independent of the
rotating interlock portion 70 and the rotating expandable portion,
and thus suppresses the rotation of the handle that is connected to
the proximal portion of the outer tube 30. Therefore, the usability
of the medical device 10 is improved.
[0049] Moreover, the slide portion 50 is disposed to be in contact
with the guide convex portion 22 that restricts the rotation of the
slide portion 50, and transmits the rotation force to the slide
portion 50. Accordingly, the slide portion 50 receives the rotation
force from the guide convex portion 22, and rotates together with
the guide convex portion 22. Therefore, the slide portion 50 can
receive a torsion force that is generated due to friction or the
like between the outer tube 30 and the interlock portion 70.
Therefore, it is possible to suppress the expandable portion 60 to
which the slide portion 50 is fixed from twisting, and maintain the
expandable portion 60 in a suitable state.
[0050] Additionally, the movement-side engagement portion 71
includes the first movement-side engagement portion 72 that
protrudes in the radial direction on the distal side of the
press-side engagement portion 32, and the outer tube 30 moves to
the distal side relative to the shaft portion 20 to cause the
press-side engagement portion 32 to be engaged with the first
movement-side engagement portion 72. Accordingly, by causing the
outer tube 30 to move to the distal side or in the distal
direction, it is possible to press the first movement-side
engagement portion 72 by the press-side engagement portion 32, and
to cause the interlock portion 70 and the slide portion 50 to move
to the distal side or in the distal direction. The slide portion 50
moves to the distal side, so that the expandable portion 60 that is
positioned between the fixing portion 40 and the slide portion 50
expands outward in the radial direction. Therefore, the medical
device 10 can adjust the diameter of the rotating expandable
portion 60 as desired for destroying the object in a rotation
state.
[0051] Moreover, the movement-side engagement portion 71 includes
the second movement-side engagement portion 73 that protrudes in
the radial direction on the proximal side of the press-side
engagement portion 32, and the outer tube 30 moves to the proximal
side relative to the shaft portion 20 to cause the press-side
engagement portion 32 to be engaged with the second movement-side
engagement portion 73. Accordingly, by causing the outer tube 30 to
move to the proximal side or in the proximal direction, it is
possible to press the second movement-side engagement portion 73 by
the press-side engagement portion 32, and to cause the interlock
portion 70 and the slide portion 50 to move to the proximal side or
in the proximal direction. The slide portion 50 moves to the
proximal side to apply a force toward the proximal side on the
distal portion of the shaft portion 20 via the fixing portion 40.
Accordingly, it is possible to bend the shaft portion 20. When the
bent shaft portion 20 is rotated, the distal portion of the shaft
portion 20 swings around, meaning the path of movement of the bent
shaft portion 20 is larger than if the shaft portion 20 rotated
while not bent. Accordingly, the expandable portion 60 that is
rotationally driven by the swinging-around shaft portion 20 can
expand a range in which a breaking effect acts.
[0052] Moreover, the expandable portion 60 becomes a first expanded
state in a natural state where no external force acts, and
outwardly expands in the radial direction more than in the first
expanded state by the movement-side engagement portion 71 moving to
the distal side relative to the shaft portion 20. Accordingly, the
object can be broken by the expandable portion 60 in the first
expanded state, and can be effectively broken by the expandable
portion 60 having a larger diameter resulting from the further
outward expansion.
[0053] Moreover, the press-side engagement portion 32 is capable of
separating from the first movement-side engagement portion 72.
Accordingly, only in a case where the expandable portion 60 is
caused to outwardly expand, it is possible to make the press-side
engagement portion 32 closer to the first movement-side engagement
portion 72, to press the first movement-side engagement portion 72
by the press-side engagement portion 32. Therefore, it is possible
to suppress the expandable portion 60 from unintentionally
expanding, so that safety is improved. Moreover, the press-side
engagement portion 32 is capable of separating from the second
movement-side engagement portion 73. Accordingly, only in a case
where a range to be covered by the breaking effect of the
expandable portion 60 is desired to be increased, it is possible to
make the press-side engagement portion 32 closer to the second
movement-side engagement portion 73, and press the second
movement-side engagement portion 73 by the press-side engagement
portion 32. Therefore, it is possible to suppress the range to be
covered by the breaking effect of the expandable portion 60 from
unintentionally expanding, so that the safety is improved.
[0054] Moreover, surfaces of the press-side engagement portion 32
and the first movement-side engagement portion 72 to be engaged
with each other or in contact with each other are perpendicular to
the axial center (center axis) of the shaft portion 20. Therefore,
it is possible to press the first movement-side engagement portion
72 that rotates by the press-side engagement portion 32 that does
not rotate, without hindering the rotation. Moreover, surfaces of
the press-side engagement portion 32 and the second movement-side
engagement portion 73 to be engaged with each other are
perpendicular to the axial center of the shaft portion 20.
Therefore, it is possible to press second movement-side engagement
portion 73 that rotates by the press-side engagement portion 32
that does not rotate, without hindering the rotation.
[0055] Moreover, the interlock portion 70 includes the first
receiving portion 74 formed with an inner peripheral surface that
slides with an outer peripheral surface of the shaft portion 20,
and the second receiving portion 75 formed with an inner peripheral
surface that slides with an outer peripheral surface of the outer
tube 30. Accordingly, the interlock portion 70 is disposed
accurately and coaxially with the shaft portion 20 and the outer
tube 30. Accordingly, the first movement-side engagement portion 72
and the second movement-side engagement portion 73 are engaged with
the press-side engagement portion 32 at suitable positions.
Accordingly, it is possible to smoothly and effectively move the
first movement-side engagement portion 72 and/or the second
movement-side engagement portion 73, by the press-side engagement
portion 32.
[0056] Moreover, the medical device 10 according to the present
embodiment is the medical device 10 for destroying the thrombus B
(object) in a blood vessel (body lumen), and includes: the
elongated shaft portion 20 that is rotationally driven; the
expandable portion 60, including the wire rods 61 having shape
memory characteristics, that is provided to the distal portion of
the shaft portion 20, and outwardly expands by a self-elastic or
self-expansion force from a contracted state by moving in the axial
direction by the first distance L1; the fixing portion 40 that
fixes the distal end of the expandable portion 60 and the shaft
portion 20; the slide portion 50 that is fixed to the proximal end
of the expandable portion 60, and is interlocked with the shaft
portion 20 slidably in the axial direction; the distal side stopper
23 and the proximal side stopper 24 that are provided to the shaft
portion 20, and restrict the movement of the slide portion 50; and
the outer tube 30 that is movable in the axial direction along the
shaft portion 20, and causes the slide portion 50 to move, in which
a distance between the distal side stopper 23 and the proximal side
stopper 24 is longer than the first distance L1, and an expanded
diameter of the expandable portion 60 becomes, by causing the outer
tube 30 to move such that the second distance L2 between the slide
portion 50 and the distal side stopper 23 in a state where the
expandable portion 60 has expanded by the self-elastic force,
larger than the expanded diameter in the expanded state by the
self-elastic force.
[0057] The medical device 10 configured as the above can restrict
the expansion of the expandable portion 60 by restricting the
movement of the slide portion 50 by the distal side stopper 23.
Therefore, it is possible to suppress the expandable portion 60
from expanding beyond the assumption, and reduce a burden of a
target body lumen. Meanwhile, for example, there is a case where
the expandable portion 60 cannot expand to an assumed expanded
diameter by only the self-elastic or self-expanding force because
an object such as a thrombus in the target body lumen is hard. In
this case, the operator can enlarge the expanded diameter of the
expandable portion 60 by manually operating the medical device 10.
In other words, the operator causes the outer tube 30 to move to
cause the slide portion 50 to move, and thus can obtain the
expanded diameter larger than the assumed expanded diameter in the
natural state. Accordingly, the operator can arbitrarily increase
the breaking force of the expandable portion 60. Note that, even in
a case where the operation is made so as to make the expanded
diameter of the expandable portion 60 large, when the expandable
portion 60 is in contact with an object to be broken in the body
lumen, there is a possibility that the expanded diameter in
appearance does not become large. However, even in such a case, the
expandable portion 60 has an expanded diameter in a state where no
force is received from an object to be cut larger than the assumed
expanded diameter in the natural state.
[0058] Moreover, the first distance L1 is longer than the second
distance L2. Accordingly, the degree of expansion of the expandable
portion 60 that self-expands by the first distance L1 is larger
than the degree of expansion of the expandable portion 60 that
further expands by the second distance L2. Therefore, the
expandable portion 60 that has self-expanded by the first distance
L1 can be mainly used. Further, the expandable portion 60 that has
further expanded within the range of the second distance L2 to
improve the breaking force can be used for additional breaking. At
this time, the second distance L2 for additionally increasing the
breaking force is shorter than the first distance L1 for causing
the expandable portion 60 to self-expand, so that the safety of the
medical device 10 is improved.
[0059] Moreover, the medical device 10 further includes the
interlock portion 70 that rotatably houses therein the shaft
portion 20, and is movable in the axial direction along the shaft
portion 20, in which the outer tube 30 includes the press-side
engagement portion 32 that protrudes in the radial direction, the
interlock portion 70 includes the movement-side engagement portion
71 that protrudes in the radial direction on at least one of the
distal side or the proximal side of the press-side engagement
portion 32, and the outer tube 30 moves to engage the press-side
engagement portion 32 with the movement-side engagement portion 71
to cause the interlock portion 70 to move, so that the slide
portion 50 moves.
[0060] In the medical device 10 configured as the above, the outer
tube 30 is caused to move in the axial direction to cause the
press-side engagement portion 32 to press the movement-side
engagement portion 71, so that it is possible to cause the
interlock portion 70 and the slide portion 50 to move to the distal
side or the proximal side. The slide portion 50 moves to the distal
side or the proximal side to deform the expandable portion 60 that
is positioned between the fixing portion 40 and the slide portion
50. Therefore, in the medical device, during when the rotating
expandable portion 60 breaks the object, it is possible to adjust
the breaking force of the expandable portion 60.
[0061] This disclosure is not limited to the above-described
embodiment, as various changes by those skilled in the art can be
made within the technical scope of this disclosure. For example,
the body lumen into which the medical device 10 is inserted is not
limited to the blood vessel, but may be the vessel, the ureter, the
bilary duct, the oviduct, or the hepatic duct, for example.
Accordingly, an object to be destroyed (e.g., crushed or cut) does
not need to be the thrombus B.
[0062] Moreover, in the abovementioned embodiment, because the
shaft body 21 is flexible, by moving the operation handle 83 to the
proximal side, the shaft body 21 is bent, so that it is possible to
increase the range covered by the breaking force (see FIG. 5).
However, it is also possible to make the shaft body 21 difficult to
bend, by setting the flexural rigidity of the shaft body 21 that is
positioned in the inner side of the expandable portion 60 harder.
In this case, by causing the operation handle 83 to move to the
proximal side, the slide portion 50 is separated from the fixing
portion 40, and the diameter of the expandable portion 60 is
reduced. Therefore, it is possible to decrease the breaking force
of the expandable portion 60 by adjusting the movement amount of
the operation handle 83. Accordingly, the medical device 10 may
only include the second movement-side engagement portion 73,
without including the first movement-side engagement portion
72.
[0063] Moreover, the wire rods 61 included in the expandable
portion 60 do not need to be spiral-shaped, but may be linear in
the axial direction in a circumferential development view, for
example.
[0064] Moreover, either one of the press-side engagement portion 32
and the first movement-side engagement portion 72 that are engaged
with each other does not need to be provided on the entire
circumference at over 360 degrees. The press-side engagement
portion 32 and the first movement-side engagement portion 72 can be
engaged with each other while allowing the relative rotation, even
when one of the press-side engagement portion 32 and the first
movement-side engagement portion 72 is partially provided in the
circumferential direction. Similarly, either one of the press-side
engagement portion 32 and the second movement-side engagement
portion 73 that are engaged with each other does not need to be
provided on the entire circumference at over 360 degrees. Moreover,
although in the present embodiment, the press-side engagement
portion 32 protrudes outward in the radial direction, and the first
movement-side engagement portion 72 and the second movement-side
engagement portion 73 protrude inward in the radial direction, the
reverse configuration may be employed.
[0065] Moreover, as in a modification example illustrated in FIG.
6, the medical device does not need to include an interlock portion
that is fixed to the slide portion 50. In this case, the outer tube
30 moves to the distal side, so that the outer tube 30 directly
presses the slide portion 50 to move the slide portion 50. The
slide portion 50 is relatively rotatable with the outer tube 30
while receiving a force from the outer tube 30.
[0066] The detailed description above describes embodiments of a
medical device and operational method representing examples of the
inventive medical device and operational method disclosed here. The
invention is not limited, however, to the precise embodiments and
variations described. Various changes, modifications and
equivalents can be effected by one skilled in the art without
departing from the spirit and scope of the invention as defined in
the accompanying claims. It is expressly intended that all such
changes, modifications and equivalents which fall within the scope
of the claims are embraced by the claims.
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